Preconditioning batteries of unmanned aerial vehicles

ABSTRACT

A method of preconditioning a battery for use in an unmanned aerial vehicle unmanned aerial vehicle may include fluidly coupling a fluid channel of a thermal management apparatus to an opening in fluid communication with the battery, determining a predicted temperature change of the battery as a result of the unmanned aerial vehicle traversing a predetermined flight path, determining a target initial temperature for the battery, wherein the target initial temperature is based at least in part on the predicted temperature change and is configured to operate the battery within a preferred temperature range during traversal of the predetermined flight path, selectively actuating a covering of the opening to allow air from the fluid channel of the thermal management apparatus to the battery, and at least one of heating or cooling the battery to the target initial temperature by directing air to the battery.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.16/731,608, filed Dec. 31, 2019 and titled “System and Method forPreconditioning Batteries of Unmanned Aerial Vehicles,” which claimspriority to U.S. Provisional Patent Application No. 62/940,201, filedNov. 25, 2019 and titled “System and Method for PreconditioningBatteries of Unmanned Aerial Vehicles,” the disclosure of each of whichis hereby incorporated herein by reference in the entirety and for allpurposes.

FIELD

The described embodiments relate generally to unmanned aerial vehicles,and, more particularly, to systems and methods for heating and/orcooling batteries of unmanned aerial vehicles.

BACKGROUND

Unmanned aerial vehicles (UAVs) are increasing in popularity for variousapplications. For example, UAVs are prevalent among hobbyists andenthusiasts for recreation, and are increasingly considered as viablepackage delivery vehicles. UAVs take many forms, such as rotorcraft(e.g., helicopters, quadrotors) as well as fixed-wing aircraft. UAVs mayalso be configured for different degrees of autonomy and may havevarying complexity. For example, simple UAVs having only basic avionicsmay be controllable only by a human-operated remote control. Morecomplex UAVs may be configured with sophisticated avionics and advancedcomputers, and may be configured for fully autonomous and/orsemi-autonomous flight.

Thrust for fixed-wing UAVs may be provided by propellers driven byelectric motors. Power for the electric motors may be provided byon-board batteries. Batteries may be rechargeable so that they can beused for multiple flights. In some cases, batteries may be removablefrom the UAVs so that spent batteries can be replaced with chargedbatteries. In this way, a UAV need not be grounded during recharging,thus increasing the available flight time for the UAV.

SUMMARY

A battery preconditioning system may include a battery for an unmannedaerial vehicle (UAV), a thermal analysis system configured to predict,for a predetermined flight path of an upcoming flight, a temperaturechange of the battery as a result of the UAV traversing thepredetermined flight path, and determine a target initial temperaturefor the battery. The target initial temperature is based at least inpart on the predicted temperature change and is configured to limit aduration that the battery operates outside an operating temperaturewindow during traversal of the predetermined flight path. The batterypreconditioning system may also include a thermal management systemconfigured to receive the target initial temperature from the thermalanalysis system and thermally condition the battery by performing atleast one of heating or cooling the battery to the determined targetinitial temperature. Predicting the temperature change of the battery asa result of the UAV traversing the predetermined flight path may includepredicting the temperature of the battery at all locations along thepredetermined flight path. The battery preconditioning system mayfurther include a computer system, wherein at least some operations ofthe thermal analysis system and the thermal management system areprovided by the computer system.

The battery may include a plurality of cells and an enclosure housingthe plurality of cells and defining an air duct in thermal communicationwith the plurality of cells. The operation of thermally conditioning thebattery may include passing a stream of conditioned air through the airduct. The air duct may define an inlet and an outlet, and the enclosuremay include a movable inlet door and a movable outlet door, eachconfigured to open during the operation of thermally conditioning thebattery and to close during the flight of the UAV. The air duct maydefine an inlet and an outlet, and the inlet and the outlet may beconfigured to be sealed closed by a component of the UAV.

The battery may include an enclosure and a plurality of cells positionedwithin the enclosure. The thermal management system may be positioned atleast partially within the enclosure and retained to the battery.

The battery preconditioning system may further include a batterycharging system configured to charge the battery and the thermalmanagement system may be configured to, while charging the battery andbefore heating or cooling the battery to the determined target initialtemperature, perform at least one of heating or cooling the battery to atarget charging temperature.

A method of preconditioning a battery for use in an unmanned aerialvehicle may include predicting a temperature change of a battery of anunmanned aerial vehicle (UAV) as a result of the UAV traversing apredetermined flight path, determining a target initial temperature forthe battery, wherein the target initial temperature is based at least inpart on the predicted temperature change and is configured to limit aduration that the battery operates outside an operating temperaturewindow during traversal of the predetermined flight path, at least oneof heating or cooling the battery to the determined target initialtemperature, installing the battery in a fuselage of the UAV, launchingthe UAV, and directing the UAV to fly along the predetermined flightpath. The method may further include, prior to heating or cooling thebattery to the determined target initial temperature, charging thebattery and while charging the battery, performing at least one ofheating or cooling the battery to a target charging temperature.

The predicted temperature change may be at least partially based on adegradation level of the battery. The degradation level of the batterymay be estimated based at least in part on a number of charge cycles towhich the battery has been subjected. The predicted temperature changemay be at least partially based on a predicted ambient temperature of anexternal environment of the UAV during at least a portion of thepredetermined flight path. The predicted temperature change may be atleast partially based on a predicted amount of heat transferred betweenthe battery and an external environment of the UAV during at least aportion of the predetermined flight path.

The operation of at least one of heating or cooling the battery mayinclude passing a stream of air through an enclosure of the battery. Theoperation of at least one of heating or cooling the battery may include,prior to passing the stream of air through the enclosure of the battery,positioning the battery on a thermal management apparatus and opening atleast one door of the battery to fluidly couple an air duct of thethermal management apparatus with an interior of the battery.

An unmanned aerial vehicle may include a fuselage, a wing coupled to thefuselage, and a battery removably coupled to the fuselage. The batterymay include a plurality of cells, an enclosure housing the plurality ofcells and defining an air duct in thermal communication with theplurality of cells, wherein the air duct defines an inlet and an outletand is configured to receive a stream of treated air from a thermalmanagement apparatus when the battery is decoupled from the fuselage andcoupled to the thermal management apparatus, and the treated air isconfigured to at least one of heat or cool the plurality of cells to atarget temperature.

The battery may include a movable inlet door and a movable outlet door,each configured to be openable when the battery is decoupled from thefuselage and closed when the battery is coupled to the fuselage. Theunmanned aerial vehicle may further include door closure featuresconfigured to force the movable inlet door and the movable outlet doorclosed when the battery is coupled to the unmanned aerial vehicle, andthe movable inlet door and the movable outlet door are configured to beforced open by a thermal management apparatus when the battery iscoupled to the thermal management apparatus. The unmanned aerial vehiclemay include sealing components configured to seal the inlet and theoutlet closed when the battery is coupled to the fuselage.

A method of preconditioning a battery for use in an unmanned aerialvehicle may include predicting a temperature change of a battery of anunmanned aerial vehicle (UAV) as a result of the UAV traversing apredetermined flight path, and determining a target initial temperaturefor the battery, wherein the target initial temperature is based atleast in part on the predicted temperature change and is configured tolimit a duration that the battery operates outside an operatingtemperature window during traversal of the predetermined flight path.The method may further include selecting, from a set of candidatebatteries, a candidate battery having an actual temperature that isclosest to the target initial temperature, at least one of heating orcooling the selected candidate battery from the actual temperature tothe determined target initial temperature, installing the selectedcandidate battery in a fuselage of the UAV, launching the UAV, anddirecting the UAV to fly along the predetermined flight path. The set ofcandidate batteries may include a first subset of candidate batterieshaving a first actual temperature and a second subset of candidatebatteries having a second actual temperature different from the firstactual temperature.

A method of preconditioning a battery for use in an unmanned aerialvehicle unmanned aerial vehicle may include fluidly coupling a fluidchannel of a thermal management apparatus to an opening in fluidcommunication with the battery, determining a predicted temperaturechange of the battery as a result of the unmanned aerial vehicletraversing a predetermined flight path, determining a target initialtemperature for the battery, wherein the target initial temperature isbased at least in part on the predicted temperature change and isconfigured to operate the battery within a preferred temperature rangeduring traversal of the predetermined flight path, selectively actuatinga covering of the opening to allow air from the fluid channel of thethermal management apparatus to the battery, and at least one of heatingor cooling the battery to the target initial temperature by directingair to the battery.

A method of conditioning a battery for use in an unmanned aerial vehicleunmanned aerial vehicle may include determining a target batterytemperature for the battery of the unmanned aerial vehicle based onflight conditions for a planned flight path of the unmanned aerialvehicle, wherein the target battery temperature is configured to limit aduration that the battery operates above or below a thresholdtemperature during traversal of the planned flight path, fluidlycoupling a channel of the thermal management apparatus to an opening influid communication with one or more cells of the battery to perform atleast one of heating or cooling the battery to the target chargingtemperature. The method may also include at least one of heating orcooling the battery to the target battery temperature, wherein theheating or cooling is based on a predicted temperature change of thebattery as a result of the unmanned aerial vehicle traversing theplanned flight path, and wherein the operation of at least one ofheating or cooling the battery comprises passing a stream of air fromthe channel to the battery, and clearing the unmanned aerial vehicle forlaunch when the battery is at the target battery temperature.

An unmanned aerial vehicle battery conditioning system may include theunmanned aerial vehicle including a fuselage, and a battery removablycoupled to the fuselage, the battery including a plurality of cells, andan enclosure housing the plurality of cells, an inlet and an outlet onan external surface of the unmanned aerial vehicle, the inlet and theoutlet selectively covered by one or more doors, and an air ductextending from the inlet and outlet to the plurality of cells. Thesystem may also include a thermal management apparatus including athermal analysis system configured to determine a target temperature forthe battery, wherein the target temperature is based at least in part apredicted temperature change of the battery as a result of the unmannedaerial vehicle traversing a predetermined flight path, and a thermalmanagement system fluidly coupled to the inlet and the outlet to providetreated air configured to at least one of heat or cool the battery tothe target temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 depicts an example unmanned aerial vehicle (UAV);

FIG. 2 depicts a battery management system;

FIG. 3 depicts an example method of thermally preconditioning a battery;

FIGS. 4A-4D depict example temperature profiles of a battery for examplemission flight paths;

FIG. 5 depicts an example battery for a UAV;

FIGS. 6A-6B depict a partial cross-sectional view of an example batteryfor a UAV;

FIG. 7A is a partial cross-sectional view of an example battery for aUAV coupled with a thermal management apparatus;

FIG. 7B is a partial cross-sectional view of the battery of FIG. 7Acoupled with a UAV;

FIG. 8A is a partial cross-sectional view of an example battery for aUAV prior to being coupled with a thermal management apparatus;

FIG. 8B is a partial cross-sectional view of the battery of FIG. 8Acoupled with a thermal management apparatus;

FIG. 8C is a partial cross-sectional view of the battery of FIG. 8Acoupled with a UAV;

FIG. 9 depicts another example UAV; and

FIGS. 10A-10B are partial cross-sectional views of the UAV of FIG. 9 .

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following description is not intended to limit the embodiments toone preferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims.

The concepts set forth herein are generally directed to electricvehicles with removable, rechargeable batteries that provide electricalpower for the motors of the electrical vehicles. The instant applicationuses unmanned aerial vehicles (UAVs) for illustrative purposes, thoughthe concepts described herein are applicable to other types of electricvehicles as well, such as cars, trucks, boats, motorcycles, scooters,industrial equipment, robots, etc.

Rechargeable batteries, such as those used for UAVs, electric cars, andthe like, do not last forever, however, and their useful life and theirefficiency may degrade with time and use. Battery parameters such asefficiency and longevity may depend on various factors. For example,battery efficiency during discharge (e.g., when the battery is poweringa load such as a propulsion motor) may depend in part on the temperatureof the battery during discharge. Further, battery longevity, or thenumber of times it can be effectively recharged and used for aparticular application, may be affected by the amount of time that abattery remains above a threshold temperature, in addition to otherfactors such as age of the battery, a number of charge/discharge cyclesthe battery has undergone, and the like.

In applications where batteries are frequently subjected to rechargecycles, and in which batteries are both a critical component in theapplication as well as a significant expense, maximizing batteryefficiency and longevity may be highly advantageous. For example, anUnmanned Aerial System (UAS) may employ multiple UAVs and multipleswappable batteries to power the UAVs. Careful thermal management of thebatteries may help increase the useful life of the batteries. Forexample, by minimizing the amount of time that a battery spends above athreshold temperature, the life of the battery may be maximized, thusincreasing UAV range and decreasing costs associated with disposing ofold batteries and purchasing new ones.

Conventionally, batteries and/or battery powered devices may includethermal protection for batteries. For example, devices may be shut downto protect the battery if the battery temperature is too high. This typeof reactive thermal management has several drawbacks. For example, inthe context of UAVs (or other electric vehicles), it may be unsafe toallow a battery to simply shut down if an over-temperature condition isdetected while the UAV is flying, as it may result in a crash. In thecontext of the UAS described herein, however, more proactive thermalmanagement may be employed to help increase battery life and providegreater battery efficiency and effectiveness.

In particular, the instant application describes systems and methodswhereby batteries for UAVs may be thermally preconditioned before theyare placed in UAVs and used to power the UAV for a mission. Morespecifically, the batteries may be heated or cooled to a target initialtemperature that is based on the exact, expected, approximate, orpredicted flight path for the mission, as well as the current orpredicted weather and/or thermal conditions expected for the flightpath. For example, the UAS may predefine flight paths for UAV missions.A flight path may, for example, correspond to a round-trip flight to aparticular location at a particular time to deliver a package or otherpayload, and may define the position of the UAV in three-dimensionalspace for the duration of the mission. Using the known flight path, aswell as other factors, such as the predicted air temperature along theflight path, a thermal analysis system of the UAS may predict how thetemperature of the battery will change as a result of the mission.Notably, the UAS may determine a specific predicted temperature changeof the battery as a result of the mission, and not merely make a generalprediction or guess that the temperature of the battery may change.

Based on the predicted temperature change, the thermal analysis systemmay determine a target initial temperature for the battery for thatparticular mission, and cause the battery to be heated or cooled to thattarget initial temperature. The target initial temperature may beselected to achieve various possible outcomes. For example, the targetinitial temperature may be selected to minimize the amount of time thata battery will spend above an upper threshold temperature during theflight. As another example, the target initial temperature may beselected to maximize the amount of time that a battery will spend abovea lower threshold temperature during the flight. As another example, thetarget initial temperature may be selected to maximize the amount oftime that a battery will spend within a temperature range during theflight. By predicting the temperature change of a battery due to flyingalong a given flight path, and thermally preconditioning the batterybased on the predicted temperature change, the batteries may spend moretime operating within an optimal range of conditions and/or less timeoperating in conditions that are damaging to the batteries, thusincreasing their life span and decreasing costs of running the UAS.Further, because the entire flight path is known prior to the mission,and because predicted weather and ambient temperature are alsoconsidered, the selection or determination of the target initialtemperature may be more effective in producing optimal batterytemperatures during flight than other methods of batterypreconditioning.

FIG. 1 depicts an example UAV 100. The UAV 100 may include a fuselage102, a wing structure 104, a tail section 106, and a motor module 108.The fuselage 102 may be formed from a substantially rigid load bearingframe and a polymer foam body that at least partially encapsulates theframe, and may have a shape that provides lift to the UAV during flight,in addition to the wing structure 104. (As used herein, flight may referto sustained flight operations as well as takeoff and landingoperations.) The polymer foam of the body may have low thermalconductivity, such that components of the UAV within the fuselage 102may be insulated from the air outside the fuselage 102 during flight.Other methods of insulation may also be used to achieve the same result.

The wing structure 104 may provide lift to the UAV during flight, andmay be releasably coupled to the fuselage 102. The wing structure 104may be part of a single, integrated structure that includes a first wingsegment on one side of the fuselage 102, a second wing segment on anopposite side of the fuselage, and a central section between and joiningthe first and second segments. The wing structure 104 may includemovable flight control surfaces, which may be or may resemble flaps. Theflight control surfaces may be configured to move to control and/orchange the attitude of the UAV in flight (e.g., to change the pitchand/or roll of the UAV 100). Other configurations of the wing structure104 and how it couples to the fuselage are also contemplated.

The tail section 106 may also include movable flight control surfacesthat may move to control the attitude of the UAV 100 during flight. Thetail section 106 may be attached to the fuselage 102 via a tail support107 that may be attached to an internal load bearing frame of thefuselage 102. The tail support 107 may have a hollow interior channelthat carries wires for electrically connecting the actuators and/orother tail-mounted electronics to the avionics of the UAV 100.

The motor module 108 may include one or more motors for propelling theUAV 100 during flight. As shown, the motor module 108 includes twopropellers, which are configured to act in concert to propel the UAV100. In other cases, more or fewer propellers may be used. The motormodule 108 (and/or the motors included in the motor module 108) mayreceive electrical power from the battery 110 to power the motors andprovide propulsion to the UAV 100.

The UAV 100 may also include a battery 110 that is attached to thefuselage 102. The battery 110 may provide power for the UAV 100. Forexample, the battery 110 may provide electrical power for the avionicsand optionally any electric motors and/or other components on the UAV100. The battery 110 may be removable from the fuselage 102 tofacilitate easy swapping. In some cases, the battery 110 may bepositioned in a battery receptacle 112 defined in the fuselage 102. Thebattery 110 may include multiple individual battery cells, which may beconnected together in series, parallel, series-parallel, or any othersuitable configuration. The battery 110 may include a housing with cellscontained therein.

The battery 110 and the UAV 100 may include physical and electricalcoupling mechanisms to retain the battery 110 to the fuselage 102 and toelectrically couple the battery 110 to electrical components of the UAV100. In one embodiment the battery 110 may define exterior surfaces ofthe UAV 100. These exterior surfaces may provide various functionality,including acting as a heat exchanger (e.g., a heat sink) for batteriesinside the battery 110. In another embodiment, the battery 110 may becoupled to the UAV 100 and then enclosed by a cover (either a separateshell or a portion of the fuselage 102) that provides aerodynamic shapeand insulation. In some cases the battery 110 may be configured to beheated and/or cooled in-flight. In some cases, the UAV 100 includessupply and/or exhaust ducts 114 that direct air over and/or through thebattery 110. Supply and exhaust ducts, as well as other techniques forheating and/or cooling a battery in flight or on the ground, aredescribed herein.

The battery 110 may be removably attached to the fuselage 102 via areleasable coupling. More particularly, the battery 110 may be removedfrom the fuselage 102 for charging, conditioning, and/or maintenance.The batteries for the UAVs may be standardized so that batteries can beswapped between and among different UAVs.

The UAV 100 shown and described with respect to FIG. 1 is merely oneexample UAV that may be used in conjunction with the batterypreconditioning systems and techniques described herein. Indeed, thedisclosed battery preconditioning concepts may be used with other typesand configurations UAVs (including, but not limited to, fixed-wingaircraft and rotorcraft) or other battery-powered vehicles.

Battery related components of the UAS, such as battery chargers, batterymonitoring equipment, battery thermal conditioners, and the batteriesthemselves, are managed by the battery management system 200. Apart fromcharging, thermally conditioning, and monitoring batteries, the batterymanagement system 200 selects batteries for installation in UAVs basedon the energy requirements and the thermal requirements of a givenmission or flight path. The battery management system 200 determinestarget initial temperatures for batteries and either selects batteriesthat are already at the determined target initial temperature or causesselected batteries to be thermally preconditioned to the determinedtarget initial temperatures prior to being used for the missions.

FIG. 2 illustrates the components of a battery management system 200according to one example embodiment. In this embodiment, the batterymanagement system 200 comprises a battery manager 202, a batterymonitoring system 206, a battery database 204, a battery charging system208, a battery interface system 210, a battery automation system 212, athermal analysis system 214, a thermal management system 216, and abattery inventory 218.

The battery inventory 218 comprises a number of batteries (such as thebattery 110, FIG. 1 ) that can be used to power electric vehicles. Thisdisclosure has primarily discussed electric UAVs, however the batteriescould be used to power other electric vehicles, such as, for example,electric cars, electric scooters, industrial equipment, robots, etc. Thebatteries in the battery inventory 218 may be coupled to or includebattery sensors that facilitate monitoring of the batteries by thebattery monitoring system 206. The battery sensors may be part of thebatteries themselves, or they may be separate instruments that are partof the battery monitoring system 206 that can be attached to anddetached from the batteries. The battery sensors may include thermalsensors (e.g., temperature sensors, thermocouples, etc.), power sensors,voltage sensors, or the like.

The battery monitoring system 206 uses the battery sensors to detectproperties of each battery (and optionally individual battery cells inthe batteries) in the battery inventory 218. Detecting properties of abattery may include sensing, calculating, estimating, or otherwisedetermining values, properties, or other characteristics of a battery.The detected properties may be reported as, or may be used to generate,battery information for each battery. Battery information may includethe voltage and output current at the battery's electrodes, the amountof electrical energy stored in the battery (sometimes referred to hereinas “charge level”), the storage capacity of the battery (sometimesreferred to herein as “capacity” or “storage capacity”), the temperatureof the battery, the number of charge and discharge cycles the batteryhas undergone, and the rate of change in voltage and output current whenthe battery is charged or discharged. The battery information may alsoinclude data about the chemical and physical state of the battery'scells, electrodes, and electrolytes, or other components. As usedherein, both the amount of electrical energy stored in a battery and thestorage capacity of the battery may be measured with the same unit(e.g., Watt-hours or Amp-hours). However, for a given battery, thevalues of these properties may be different. For example, a battery witha capacity of 100 Watt-hours may be charged to 50% of its capacity, andthus have a charge level of 50 Watt-hours.

The battery information can be used to determine many aspects of abattery's condition. For example, the battery information can be used todetermine the energy storage capacity for each battery, the usefulremaining operational life for each battery, the charge level of eachbattery, the predicted capacity degradation for each battery (e.g., thereduction in the energy storage capacity of the battery as compared toan ideal or a previously measured energy storage capacity), thelikelihood of failure of each battery, etc. These determinations can bemade by the battery manager 202, or by other modules in the UAS.

At least some of the battery information, which the battery monitoringsystem 206 gathers from the batteries, may be stored into a batterydatabase 204. The battery database 204 is a device that provides meansfor storing information durably. In one embodiment, the battery database204 may be a computer with a hard drive or a solid state drive (or someother means for storage) running a software database system such asMYSQL, POSTGRES SQL, MONGODB, etc. In another embodiment the batterydatabase 204 is a software program running on a cloud service, such asAMAZON WEB SERVICES, GOOGLE CLOUD, etc. In another embodiment thebattery database 204 is part of the battery manager 202, or executes onthe same computer hardware as the battery manager 202.

The battery charging system 208 may comprise a single charging devicethat can be coupled to one or more batteries in the battery inventory218, or it may comprise several independent devices that can charge manybatteries. In one embodiment, the battery charging system 208 comprises,communicates with, and/or controls a rack charger 220 that can becoupled to many batteries simultaneously. The battery charging system208 receives instructions from the battery manager 202 identifyingtarget charge specifications for batteries (either individually orcollectively), and charges the batteries to achieve the target chargespecifications. The rack charger 220 may electrically couple to thebatteries (e.g., via battery terminals on the batteries andcomplementary connectors on the rack charger 220) to charge and/ordischarge the batteries. The rack charger 220 may also communicativelycouple to the batteries (e.g., via communications connectors on thebatteries and the rack) to facilitate communications between thebatteries (and onboard sensors, computers, and the like) and the batterymanagement system 200. The rack charger 220 may also include thermalsystems, such as air conditioning systems, fans, ducting, and othersystems for heating and/or cooling the batteries during variousoperations and in anticipation of missions. Additional details of thethermal systems are described herein.

The battery monitoring system 206 may report one or more properties orcharacteristics of the batteries to the battery manager 202 duringcharging to enable the battery manager 202 to issue charginginstructions to the battery charging system 208 to stop charging,increase or decrease the rate of charging, change the target chargespecifications for the batteries, or the like. The battery manager 202may issue charging instructions in several different ways. In oneembodiment the charge specification includes a target output voltage foreach battery, and the battery charging system 208 will apply current tothe battery at a particular input voltage until the batteries show thetarget output voltage at their electrodes. In another embodiment thecharge specification includes both a target output voltage and a targetoutput current. In this embodiment the batteries are charged until theyreach the target output voltage and the target output current, and thenthe charging is stopped. In another embodiment the charge specificationincludes a target power rating (e.g., a target Watt-hour) or targetcurrent rating (e.g., Amp-hour), and the batteries are charged until thetarget power or current rating is reached. In another embodiment, thecharge specification includes a target reading from a charge sensor ofthe battery. The charge sensor is a sensor (and/or associated circuitryor other components) that is incorporated into the battery and whichindicates a level of charge of the battery (e.g., Watt-hours, Amp-hours,etc.). The battery charging system 208 may read an output from thecharge sensor via any appropriate technique, such as visual analysis ofa display, detection of an analog signal that represents or indicatesthe charge level of the battery, or receiving a digital signal thatincludes a charge level of the battery.

In one embodiment, the battery charging system 208 receives a chargespecification for one or more selected batteries and charges thebatteries based on the charge specification. The charge specificationmay instruct the battery charging system 208 to charge a battery lessthan its full energy storage capacity in order to minimize the capacitydegradation of the battery as a result of unnecessary charging.

In one embodiment, the battery charging system 208 has a safetymechanism that automatically halts the electricity flow into a batteryif it detects that the battery temperature, voltage, or current isoutside of a safety range for these properties, or if the chargespecification would exceed the storage capacity of the battery.

The battery manager 202 is a hardware or software module thatcoordinates the functioning of the other components of the batterymanagement system 200. In one embodiment, the battery manager 202 is asoftware program running on hardware that has network access to theother components of the battery management system 200. In anotherembodiment, the battery manager 202 is a software program that executeson the same computer hardware as one or more other components of thebattery management system 200.

The battery manager 202 receives battery information from the batterymonitoring system 206 and the battery database 204, as well as requestsfrom other components or systems of the UAS, and determines specificinstructions for the other components of the battery management system200. For example, the battery information received from the batterymonitoring system 206 may include information indicating that the chargein a specific battery is insufficient for a particular UAV mission, andon the basis of this information the battery manager 202 may sendinstructions to the battery charging system 208 to charge that specificbattery. If the specific battery is not already coupled to the batterycharging system 208, the battery manager 202 may also send instructionsto a battery automation system 212 or to a human operator to connect thespecific battery to the battery charging system 208.

The battery manager 202 may receive mission energy requirements,describing an amount of energy required by an electric vehicle (e.g., aUAV) to complete a mission, and the battery manager 202 may issueinstructions (e.g., battery selection instructions, chargespecifications, etc.) on the basis of the mission energy requirements.The mission energy requirements may specify a charge level needed by anelectric vehicle to complete a mission (e.g., to traverse or fly along apredetermined flight path). For example, a mission energy requirementmay specify the energy required by a UAV 100 to fly to a destinationsite along a particular route with a given wind condition, drop apayload, and return to a launch site. The mission energy requirement maybe specified in a standard unit such as Watt-hours, Amp-hours, or bysome other metric.

The mission energy requirement may specify a power requirement inaddition to a charge level. In particular, whereas the charge levelrelates to a total amount of electrical energy that the battery candeliver from a given charge, a power requirement may define a particularamount of power that may be required by the electric vehicle for part ofits mission. For example, if the UAV 100 must fly over a windy mountain,it may need an increased amount of power delivered to its motors duringits ascent as compared to the power requirement during level flight.Thus, any battery selected for such a mission will need to be able toprovide the boost of power needed for the ascent, in addition toproviding the overall amount of energy required for the rest of themission. By taking the power requirement of a mission into account inaddition to overall energy requirements, the selection and charging ofbatteries can be tailored to individual missions and flight paths. Forexample, a longer mission with lower maximum power requirements (e.g.,characterized by level flight with low winds) may be able to use abattery with a larger capacity but a lower maximum power output, whereasa shorter mission with higher maximum power requirements (e.g.,characterized by frequent altitude changes and/or windy conditions) maybe able to use a battery with a lower capacity (or a battery that ischarged to a lower charge level) but a higher maximum power output. Inthe foregoing discussion, the power requirement may be replaced and/orsupplemented with an electrical current requirement. Thus, a battery maybe selected for its ability to deliver a certain maximum electricalcurrent to the motors of the UAV 100.

In one embodiment, the battery manager 202 instructs the batterycharging system 208 to charge a battery based on the mission energyrequirements and the existing charge in the battery. For example, thebattery manager 202 may instruct the battery charging system 208 tocharge a selected battery to a specific level based on the missionenergy requirements of a particular mission (e.g., a predeterminedflight path). The battery manager 202 may also instruct the thermalmanagement system 216 to thermally condition the selected battery byheating or cooling the selected battery to a target initial temperature,as described herein. As used herein, the term “thermally conditioning”or “thermal conditioning” may include heating and/or cooling thebattery.

In one embodiment the battery manager 202 uses the battery informationand the mission energy requirements to select one or more batteries thatcan efficiently provide the energy required by an electric vehicle for aparticular mission, while at the same time balancing other concerns,such as minimization of battery degradation, maximization of batterylife, etc.

The battery manager 202 selects a battery or batteries for a particularelectric vehicle's mission based on several possible criteria andmethodologies. In one embodiment, the battery manager 202 selectsbatteries by determining a battery or batteries from the batteryinventory 218 that will have adequate capacity to satisfy the missionenergy requirements.

The capacity of the batteries can be determined using the batteryinformation from the battery monitoring system 206 and the batterydatabase 204. In some cases, the exact capacity of a battery is notknown (or is not readily determinable), but an approximate capacity canbe determined from various data. For example, in one embodiment, thepresent capacity of a battery is approximated by using an initialcapacity measurement (given by a manufacturer or measured by the batterymonitoring system 206 via a full charge and discharge of the battery),and reducing that capacity measurement based on the number ofcharge/discharge cycles of the battery that have occurred since themeasurement was taken, to obtain an approximate present capacity for thebattery. The amount that the initial capacity measurement is reduced percharge/discharge cycle can be based on the amount of capacity reductionthat was observed historically in similar batteries. In addition to thenumber of charge/discharge cycles, the approximated capacity for abattery can also be adjusted based on historical performance data forthe battery and similar batteries, the temperature at which the batterywas charged/discharged, etc.

Once a particular mission has been selected, the thermal analysis system214 may predict, for a predetermined flight path of an upcoming mission,a temperature change of the battery as a result of the UAV traversingthe predetermined flight path. The temperature change of the battery maybe predicted based at least in part on battery information of theselected battery. For example, the predicted temperature change mayaccount for the age of the battery. More particularly, some types ofbatteries have a greater temperature rise as they get older and havegone through more charge cycles. Accordingly, the predicted temperaturechange of a battery may take into account the number of charge cyclesthe battery has undergone, the overall age of the battery, or the like.The thermal analysis system 214 may also determine a target initialtemperature for the battery based at least in part on the predictedtemperature change. The target initial temperature may be determined soas to limit a duration that the battery operates outside an operatingtemperature window during traversal of the predetermined flight path. Insome cases, the target initial temperature may be determined so as toprevent (at least theoretically) the battery from operating outside theoperating temperature window during traversal of the predeterminedflight path. Additional details of the target initial temperaturedetermination are provided herein. As used herein, battery informationmay refer to parameters, data, or other information about a specificbattery, including but not limited to the battery age, actualtemperature, number of charge/discharge cycles, maximum/minimum achievedtemperature, battery chemistry, number or type of battery cells, batteryinsulation rating or type, rated capacity, and actual capacity.

Once the thermal analysis system 214 predicts the temperature change anddetermines a target initial temperature for the battery, it maycommunicate with the thermal management system 216 to cause the selectedbattery to be thermally conditioned to the target initial temperature.The thermal management system 216 may include or be operativelyconnected with thermal management apparatuses or systems for coolingand/or heating the selected battery. For example, the rack charger 220may include fluid channels or ducting that can pass air or other fluidsthrough, over, or around the batteries to heat and/or cool thebatteries. The thermal management system 216 may also include or controlair conditioners, heaters, Peltier devices, heating coils, fans, and/orother components that can heat and/or cool the batteries. The thermalmanagement system 216 may include or control the heating and/or coolingoperations of the various thermal management apparatuses to causeselected batteries to be heated and/or cooled to their target initialtemperatures. Example thermal management apparatuses and systems aredescribed in greater detail herein.

The thermal analysis system 214 and the thermal management system 216are shown as separate systems or modules in FIG. 2 , though they neednot be physically, logically, or programmatically separated in thisparticular manner. For example, the thermal analysis system 214 and thethermal management system 216 may both be executed by the same computersystem, or they may be executed by different computer systems. Further,functions and operations that are described in relation to one of thesystems may be executed by multiple different computers. Thus, thoughthey are described separately in the instant discussion, and thoughcertain functions are described as being performed by certain systems,the functions described here may be performed by different combinationsof systems or by different systems entirely. In some cases, at leastsome of the functions of the thermal management system 216 may beexecuted by computer systems that are onboard the batteries. Forexample, a battery-mounted processor may receive a target initialtemperature specification from the thermal analysis system 214 and causethermal management apparatuses (which may be onboard the battery, suchas a heating coil coupled to the battery cells, or external to thebattery, such as an air conditioner on a rack charger 220) to thermallycondition the battery to the target initial temperature.

Once a battery or batteries are selected, charged, and thermallyconditioned, the battery manager 202 may send a signal to the batteryinterface system 210 and the battery automation system 212, indicatingthe selected batteries. The latter modules can take further action, asdescribed below, based on the battery selection.

The battery interface system 210 provides a human-readable interfacethat can indicate the selected batteries in the battery inventory 218 toa human operator, as well as display data related to the batteries inthe battery inventory 218 (e.g., battery charge state, batterytemperature, number of charge/discharge cycles, etc.). The operator canperform various tasks related to the selected batteries based on theindications. For example, the operator can be informed via ahuman-readable indicator operated by the battery interface system 210that a particular battery should be installed on a particular UAV for amission.

The battery automation system 212 is a system that helps to reduce theamount of manual labor required of a human operator. The batteryautomation system 212 includes one or more devices that perform at leastsome of the tasks related to batteries in the battery inventory 218. Forexample, the battery automation system 212 may automatically perform oneor more of the following battery related tasks: installing and removingbatteries from an electric vehicle; coupling and uncoupling batteriesfrom the battery charging system 208; and coupling and uncouplingbatteries from the battery monitoring system 206. In one embodiment thebattery automation system 212 comprises a robotic arm that performsautomation tasks. In another embodiment, the battery automation system212 and the battery charging system 208 are merged into a single deviceor system that can both charge batteries and install the chargedbatteries onto a UAV.

After the battery manager 202 selects one or more batteries for anelectric vehicle's mission, the battery manager 202 may issue additionalinstructions to other modules in the battery management system 200 toprepare the batteries for the mission. For example, the battery manager202 may instruct the battery charging system 208 to charge one or moreof the selected batteries if their charge level is not sufficient tomeet the mission energy requirement. The battery manager 202 may alsoinstruct the thermal analysis system 214 to determine a target initialtemperature for the battery based on the demands of the mission (andoptionally weather conditions, as described herein), and optionallyinstruct the thermal management system 216 to heat or cool the batteryto the determined target initial temperature. The battery manager 202may issue instructions to the battery interface system 210 (to inform anoperator) or the battery automation system 212, to couple specificselected batteries to the battery charging system 208, or to installspecific selected batteries to an electric vehicle.

The battery manager 202 may also improve the battery selection processby gathering information before and after electric vehicle missions. Forexample, the battery manager 202 may cause the battery monitoring system206 to take pre-mission readings of battery properties for selectedbatteries, such as the charge level, temperature, voltage at theelectrodes, electrical current output, etc. These pre-mission propertiesmay be stored in the battery database 204. The selected batteries maythen be installed into an electric vehicle for its mission (e.g. theymay be installed in a UAV for a flight). When the electric vehiclereturns after its mission, the battery manager 202 may cause the batterymonitoring system 206 to measure post-mission properties (for the samebattery properties) of the batteries in the electric vehicle. Thebattery manager 202 may also receive, from a battery or a UAV, batterydata that was logged during flight, such as discharge rates, batterytemperatures, ambient air temperatures, and the like. The pre-missionproperties, post-mission properties, and logged in-mission propertiesmay be stored in association with the battery and may be used to updateor modify battery information (e.g., charge cycles, maximum temperaturereached, minimum temperature reached, amount of time above and/or belowthreshold temperatures, and the like). These properties may also be usedto update and/or modify models that are used by the battery managementsystem 200, such as models for predicting capacity degradation,predicting temperature changes of batteries as a result of traversingflight paths, and the like.

FIG. 3 is a flow chart of an example method 300 of thermallypreconditioning a battery for use in a UAV. The method 300 may beperformed by any suitable devices and/or systems, such as the thermalanalysis system 214 and the thermal management system 216 in FIG. 2(which may be and/or include computer systems, thermal managementapparatuses, and the like).

At operation 302, a temperature change of a battery of a UAV as a resultof the UAV traversing a predetermined flight path is predicted.Predicting the temperature change may include predicting the completetemperature profile of the battery along the predetermined flight path(e.g., temperature values of the battery along the predetermined flightpath). In this way, a complete profile of the battery's temperature asit traverses the predetermined flight path can be known and analyzed(prior to launch) and used to determine a target initial batterytemperature, as described herein. FIGS. 4A-4D illustrate exampletemperature profiles of a battery along a predetermined flight path.

Predicting the temperature change of the battery is facilitated by theUAS having predetermined the entire flight path of the UAV for a givenmission. For example, the position, velocity, acceleration, direction oftravel, and other details of the flight plan are established for a givenmission prior to the UAV being launched. Accordingly, the UAS, and moreparticularly the thermal analysis system 214, can determine the expectedpower output required from the battery at any point along the flightpath. For example, if the flight path includes a climb over a mountainrange, the amount of power required by the UAV to make that maneuver,and by extension the expected power required from the battery to makethat maneuver, may be known, with some degree of confidence. The actualpower required for a specific flight may vary from the expected powerrequirement of the flight plan due to variable factors such as wind, butsuch variation is generally expected to even out over many flights(since some flights will take less than the expected power requirementswhile others take more).

The thermal analysis system 214 may base the determination of thetemperature change of the battery at least in part on the degradationlevel of the battery. In particular, for a given power output, older andmore degraded batteries may increase in temperature more than newer orless degraded batteries. Accordingly, the thermal analysis system 214may account for the age and/or degradation of the batteries to moreaccurately predict the temperature change of the selected battery forthe predetermined flight path. In some cases, a relationship betweentemperature change and power output is known for the selected battery(e.g., based on data from previous flights). The relationship betweentemperature change of a battery resulting from its power output may bereferred to herein for simplicity as a ΔT/power ratio. The ΔT/powerratio may change as a battery degradation level increases. In somecases, the degradation level, and thus the ΔT/power ratio, is based atleast in part on a number of charge cycles the battery has undergone,the age of the battery, or the like.

Where the ΔT/power ratio for a given battery is known (e.g., measuredand/or calculated using data from actual flights), the thermal analysissystem 214 may use the known mathematical relationship to predict thetemperature rise of that battery when traversing the predeterminedflight path. In other cases, a ΔT/power ratio is estimated for theselected battery based on that battery's age, degradation level, etc.For example, the thermal analysis system 214 may use a type-specific orgeneric scale that associates age and/or degradation level of batteriesof a specific type or generically with ΔT/power ratios. The thermalanalysis system 214 may thus estimate the temperature rise of a batteryalong the entire flight path, while taking into account the degradationlevel of the battery, even without knowing an actual (e.g., measured)ΔT/power ratio for that individual battery.

The thermal analysis system 214 may also account for other factors whendetermining the temperature change of the battery as a result of the UAVtraversing a predetermined flight path. For example, the thermalanalysis system 214 may determine the predicted temperature change basedat least in part on a predicted ambient temperature of an externalenvironment of the UAV during at least a portion of the predeterminedflight path. In particular, because a plan for the entire flight path isknown prior to the start of the mission, the location of the UAV inthree-dimensional space at all times during the mission is known.Accordingly, using weather forecasts, the predicted ambient temperaturearound the UAV at all times during the mission can be determined. Thisdetailed ambient temperature data, along with the temperature rise ofthe battery due to power output, allows the thermal analysis system 214to predict the temperature change of the battery to a greater degree ofaccuracy, as the prediction accounts for any heat transfer between thebattery and the air around the UAV during flight.

When predicting the temperature change of the battery, the thermalanalysis system 214 may use one or more heat transfer coefficients todefine the heat transfer rate between the battery and the outside air.The heat transfer coefficients may reflect factors such as theinsulation effect of the UAV and/or the battery pack, as well as thespeed of the air along heat transfer surfaces of the battery pack (e.g.,along surfaces of the battery pack that define external surfaces of theUAV). Thus, for example, if the flight path has the UAV travelling athigh speeds through a segment with very cold air, the predictedtemperature values of the battery along that segment may reflect thepredicted heat loss to the surrounding air (e.g., resulting in lowertemperature values than would be predicted if air temperature were nottaken into consideration). Similarly, if the flight path has the UAVtravelling through a segment with very hot air, the predictedtemperature values of the battery along that segment may reflect thepredicted heat gain from the surrounding air (e.g., resulting in highertemperature values than would be predicted if air temperature were notaccounted for).

By accounting for factors such as battery degradation, ambient airtemperature, insulation, and air speed, the thermal analysis system 214can predict the temperature change of the battery along the flight pathwith a high degree of accuracy. For example, instead of simplydetermining that a temperature rise of indeterminate value is likely tooccur during a mission or trip, the thermal analysis system 214 maypredict actual battery temperature values along the flight path, basedon numerous measured and predicted parameters (e.g., actual or predictedΔT/power ratios, predicted air temperatures, expected air speeds, actualor predicted heat transfer coefficients, etc.). This data may then beused to determine a suitable target initial temperature for the battery,as discussed herein.

At operation 304, the thermal analysis system 214 determines a targetinitial temperature for the battery. The target initial temperature maybe based at least in part on the predicted temperature change (fromoperation 302) and is configured to limit a duration that the batteryoperates outside an operating temperature window during traversal of thepredetermined flight path. More particularly, the target initialtemperature may be selected so that the temperature profile of thebattery during the mission is optimized. For example, as described ingreater detail with respect to FIGS. 4A-4D, the target initialtemperature may be determined so that the maximum temperature of thebattery during the mission does not exceed a threshold temperature, orto minimize the amount of time that a battery is above a thresholdvalue, or to achieve other possible target scenarios.

At operation 306, the battery is thermally preconditioned by performingat least one of heating or cooling the battery to the target initialtemperature. For example, the thermal analysis system 214 may providethe target initial temperature to a thermal management system 216, whichin turn initiates heating and/or cooling operations to bring the batteryto the target initial temperature.

Thermally preconditioning the battery may be achieved using varioustechniques. For example, heating the battery may be accomplished byproviding power to a heating coil or other heating apparatus that isthermally coupled with the battery (and in some cases physically residesin the battery module). In some cases, heating and/or cooling may beaccomplished by passing a stream of fluid (e.g., ambient, heated, orcooled air) through an enclosure of the battery. The battery may defineducting or fluid channels within the enclosure to facilitate this typeof thermal preconditioning. FIGS. 5-8B illustrate example configurationsof batteries that include ducts to facilitate thermal preconditioningusing forced air.

Thermally preconditioning the battery may occur simultaneously with oroverlap charging of the battery. In some cases, the battery ismaintained at a target charging temperature, during charging, using thesame thermal management apparatuses that are then subsequently used forthermally preconditioning the battery to the target initial temperature.

In some cases, the UAS may select a particular battery for use in agiven mission from a set of candidate batteries after determining thetarget initial temperature. For example, the thermal analysis system 214may select a battery, from the set of candidate batteries, that has anactual temperature that is closest to the target initial temperature (orhas an actual temperature that is equal to or less than a thresholdtemperature difference relative to the target initial temperature), andthat otherwise satisfies the requirements of the mission, such as havinga sufficient capacity. The selected battery may then be heated or cooledto reach the target initial temperature. By selecting a battery that isclosest to the target initial temperature, the energy requirements andtime required to heat or cool the battery to the target initialtemperature may be minimized, thereby improving the speed and efficiencyof the overall system. Reducing the time required for thermallypreconditioning the battery may also reduce the time between a UASreceiving a mission request and the UAV being launched. This improvementin speed may be especially beneficial where the mission is to delivermedical or other life-saving supplies or services.

The batteries of a UAS may have different actual temperatures forvarious reasons. For example, the battery management system 200 maymaintain batteries at different temperatures to help reduce thermalpreconditioning time. Batteries may also return from missions attemperatures other than the ambient temperature at the launch site orbattery storage facility. Accordingly, when those batteries are returnedto the battery inventory with elevated or reduced temperatures, they maybe selected for another mission based on their proximity to the targetinitial temperature for that mission.

After thermally preconditioning the battery to the target initialtemperature, the battery is installed in a fuselage of a UAV (operation308). This may include a human operator physically placing the thermallypreconditioned battery in a battery cavity of a UAV, or a robotic ormechanized system that positions the battery in the UAV. At operation310, the UAV is launched and directed to fly along the predeterminedflight path.

FIGS. 4A-4D illustrate example temperature profiles of a battery for aUAV for example mission flight paths. These profiles illustrate someexample ways of determining a target initial temperature for a battery.The profiles in FIGS. 4A-4D show battery temperature (T) on the y-axisand time (t) on the x-axis. The profiles represent the batterytemperature of a UAV traversing a complete flight path. The dashed-lineprofiles represent the predicted temperature of a battery along theflight path with no thermal preconditioning (e.g., with the batterystarting at an ambient temperature of the environment of the mission),and the solid-line profiles represent the predicted temperature of thebattery along the same flight path with thermal preconditioning.

FIG. 4A illustrates example temperature profiles for a given mission,including a predicted temperature profile 400 (corresponding to themission without thermal preconditioning). The profile 400 starts withthe battery at an unconditioned passive initial temperature (T_(pi)),which may correspond to the actual or forecasted ambient temperature ofthe battery's environment at the starting time of the mission. Using thetechniques described above, the thermal analysis system 214 (or anyother suitable system) may predict the temperature of the battery atpoints (or continuously) along the flight path. The profile 400 has apredicted maximum temperature (T_(pmax)) during the path, representingthe highest temperature that the battery would experience during thismission (e.g., along this particular flight path and in view of theforecasted ambient temperatures during the mission).

In some cases, it may be desirable to prevent the battery from everexceeding a threshold maximum temperature (T_(max thold)). Inparticular, the batteries may degrade faster if they are used whiletheir temperature is above a certain threshold temperature, somaintaining batteries below that temperature may help improve the usefullife of the batteries. In order to prevent the battery from reaching orexceeding T_(max thold), a target initial temperature (T_(i)) may beselected so that the temperature change of the battery along the flightpath does not reach or exceed T_(max thold). For example, as shown inFIG. 4A, T_(max) of the profile 402 (representing the predictedtemperature profile of the battery during the mission when starting atT_(i) instead of T_(pi)) is below T_(max thold). Once the T_(i) isselected, the battery may be thermally preconditioned (in this case,cooled) to T_(i) prior to the start of the mission.

The T_(max thold) of a battery may be set at a value above which thedegradation of the battery has been deemed unacceptable, and/or whereoperation may become dangerous to the battery or to the UAV. In somecases, the T_(max thold) is 60° C., 50° C., 40° C., 38° C., 35° C., 30°C., 25° C. or any other suitable temperature. In some cases, the valueof T_(max thold) is based at least partially on the type of battery. Forexample, a lithium-ion battery may have a different T_(max thold) than anickel-cadmium battery, or a nickel-metal hydride battery. T_(max thold)for any given battery may be established as a temperature at which abattery, stored at that temperature for one year at 100% charge, losesno more than 35% of its total capacity. For example, a particularbattery, when stored for one year at an initial charge level of 100% andheld at 40° C. for that year, may be found to lose around 35% of itstotal capacity. In that case, the T_(max thold) for that battery may beestablished at 40° C.

FIG. 4B illustrates temperature profiles of another example mission.This mission may have a different flight path and/or different battery,ambient temperature, and/or insulation parameters than what isrepresented in FIG. 4A. The predicted temperature profile 404(representing no thermal preconditioning) may represent a mission with aflight path in a cold climate and using a UAV/battery with a high heattransfer rate to the ambient environment. Due to the low-temperatureconditions, the profile 404 is entirely at or below a threshold minimumtemperature (T_(min thold)). For example, T_(pi) as well as T_(pmax) areat or below T_(min hold). This may be undesirable, as the batteries maynot operate as efficiently when they are below T_(min thold).Accordingly, the thermal analysis system 214 may determine a targetinitial temperature T_(i) such that the temperature of the batteryduring the actual mission does not fall below T_(min). Profile 406illustrates the predicted temperature profile of the battery during themission when starting at T_(i) instead of T_(pi), showing that thepredicted actual temperature of the battery after thermalpreconditioning is always above T_(min). In this case, thermalpreconditioning the battery may include heating the battery to T_(i)prior to the start of the mission.

FIG. 4C illustrates temperature profiles of another example mission. Inthis example, the flight path results in the battery temperature havingportions below T_(min thold) and above T_(max thold). Accordingly, thethermal analysis system 214 may determine a T_(i) that will result in adesired temperature profile, even though the maximum or minimumthresholds may still be exceeded. For example, while exceedingT_(max thold) may be suboptimal from a battery longevity perspective,because the profile 408 (representing no thermal preconditioning) isbelow T_(min thold) for a large portion of the mission, it may be morebeneficial to increase T_(i)to maintain the battery temperature aboveT_(min thold) during the mission. This may be desirable, for example, toincrease the efficiency of the battery during flight, even at theexpense of a short duration above T_(max thold). Profile 410 shows thepredicted temperature profile of the batter if the initial temperatureis raised to T_(i), illustrating how T_(max) exceeds T_(max thold), butthe temperature profile remains above T_(min thold) through the mission.

FIG. 4D illustrates temperature profiles of yet another example mission.In this example, the flight path results in maximum and minimumtemperatures that are within T_(max thold) and T_(min thold), even whenthe predicted initial temperature without thermal preconditioning T_(pi)is not altered. However, even where neither temperature threshold isexceeded, there may be benefits to thermally preconditioning thebattery. For example, it may be beneficial to keep the maximum batterytemperature as far from T_(max thold) as possible without going belowT_(min thold). Accordingly, the thermal analysis system 214 maydetermine a target initial temperature T_(i) that lowers the minimumtemperature of the flight path to be at or near T_(min thold), thuskeeping the maximum temperature to a lowest possible value (withoutexceeding T_(min thold)). The temperature profile 414 illustrates thepredicted temperature profile if the battery is cooled to T_(i) prior tothe start of the mission.

FIGS. 4A-4D show some example ways in which the target initialtemperature may differ from the ambient temperature (e.g., the initialtemperature the batteries would have if they were not thermallypreconditioned). However, these are merely some examples, and othertemperature targets and/or rule sets (and/or combinations of targetsand/or rule sets) may be used to determine target initial temperatures.For example, the thermal analysis system 214 may be configured todetermine a target initial temperature that minimizes the amount of timethat a profile spends above T_(max thold) or below T_(max thold). Asanother example, the thermal analysis system 214 may be configured todetermine a target initial temperature that maintains the averagetemperature of the battery during the mission at or near a targettemperature (e.g., 20° C., 25° C., 27° C.). As another example, thethermal analysis system 214 may be configured to determine a targetinitial temperature that maintains the battery temperature within atemperature window (e.g., between 22° C. and 27° C., between 20° C. and30° C., or any other suitable window) for as much of the mission aspossible. Other targets, rule sets, and/or selection algorithms fordetermining the target initial temperature may also be used.

FIG. 5 illustrates an example battery 500 that may be used to providepower to a UAV (e.g., the UAV 100, FIG. 1 ), or any other suitablevehicle. The battery 500 may be an embodiment of the battery 110 in FIG.1 .

In some implementations, the battery 500 (or a housing of the battery500) defines a surface 502 that defines an external surface of thefuselage when the battery 500 is installed in the vehicle. (FIG. 1further illustrates a battery defining an exterior fuselage surface.).The surface 502 may act as a heat-transfer surface between the batteryand an external environment. In other implementations, the battery 500is configured to be installed in a compartment within a vehicle, suchthat none of the battery's surfaces define an exterior fuselage surface.In some cases, the battery and/or the compartment for the batteryinclude insulation to prevent or limit heat transfer between the batteryand the exterior environment. As described herein, the battery 500 mayinclude an air duct within the battery 500 that allows air to be passedthrough the battery 500 to thermally condition the battery.

FIG. 6A illustrates a partial cross-sectional view of the battery 500,viewed along line A-A in FIG. 5 . The battery 500 may include anenclosure 602 and a plurality of cells 604 housed within the enclosure602. The battery 500 may also include other components, such as batterycontrol circuitry, heating elements, cooling elements, electrical and/ormechanical components (e.g., for electrically and/or mechanicallycoupling the battery 500 to a UAV or other vehicle), and the like.

The battery 500 may define an air duct 606 that is in thermalcommunication with the cells 604. The air duct 606 may allow air to passthrough the air duct to thermally condition the battery 500 by heatingand/or cooling the cells 604. In some cases, the air duct may allow airto pass over surfaces of the cells 604 themselves. In other cases, thecells may be at least partially encapsulated or held in a matrixmaterial, which may mechanically hold the cells 604 in a particularorientation and/or position, and may optionally act as a thermalregulator for the cells 604. For example, the matrix material may beconsidered to absorb heat from the cells 604, such as by using heat fromthe cells 604 to cause a phase change in the matrix material. In anycase, the air duct 606 is configured to facilitate heat transfer betweenthe cells 604 and air within the air duct 606.

The air duct 606 may define an inlet 614 (FIG. 6B) and an outlet 616(FIG. 6B), and the battery 500 may further include movable doors 608,610 that are configured to selectively open and close to provide accessto the air duct 606. FIG. 6A shows the battery 500 with the movabledoors 608, 610 in a closed position, while FIG. 6B shows the battery 500with the movable doors 608, 610 in an open position. When the movabledoors 608, 610 are in the open position, a stream of air 612 (or anyother suitable fluid) may be passed through the air duct 606 tothermally condition the battery 500 (e.g., heat or cool the battery).Where a stream of air is used to thermally condition a battery, the airmay be treated prior to being passed through the air duct. Treating theair may include performing any suitable process on the air so that itcan be used to heat and/or cool the battery. For example, treating theair may include heating, cooling, dehumidifying, humidifying,compressing, or any other suitable process or treatment. The air may beheated or cooled using any suitable technique, including withoutlimitation vapor compression refrigeration cycles, evaporative coolers,electric heaters, or gas (or other fuel) heaters. In some cases, insteadof air, another type of gas or fluid may be used, such as nitrogen,carbon dioxide, water, oil, or the like.

The movable doors 608, 610 may be configured to be closed while thebattery 500 is installed in a UAV, when it is not coupled to a thermalmanagement apparatus (e.g., the rack charger 220), and/or is otherwisenot being thermally conditioned. On the other hand, the movable doors608, 610 may be configured to be open when they are coupled to a thermalmanagement apparatus and/or are being thermally conditioned. In somecases, the movable doors 608, 610 may also be opened or openable whenthe battery 500 is installed in a vehicle, such as to allow the batteryto be heated and/or cooled during use.

The movable doors 608, 610 may be actuated to be opened or closed in anysuitable way. In some cases, the movable doors 608, 610 are openedand/or closed by a physical interaction between the battery 500 and athermal management apparatus, by an electromagnetic actuator (or othertype of actuator) integrated with the battery 500, or by other suitablemechanisms and/or techniques. In some cases, the battery 500 does notinclude movable doors, but instead includes openings without doors,flaps, or other movable covers. Examples of these types ofconfigurations are described herein.

FIG. 7A illustrates a partial cross-sectional view of another examplebattery 700, which may be an embodiment of the battery 110 (FIG. 1 )and/or the battery 500 (FIG. 5A), with the battery 700 positioned on athermal management apparatus 710. The battery 700 includes a pluralityof cells 704 and defines an air duct 702 in thermal communication withthe cells 704. The air duct 702 may define or be in communication withan inlet 708 and an outlet 709. The battery 700 may lack doors, flaps,covers, or other components that seal or otherwise cover the inlet andoutlet 708, 709.

When the battery 700 is coupled to a thermal management apparatus 710(which may be an embodiment of a rack charger 220, for example), airducts 712, 714 may fluidly couple to the inlet and outlet 708, 709 ofthe battery 700, thereby allowing a stream of air or other fluid 720 topass through the air duct 702 of the battery and heat and/or cool thecells 704.

As the battery 700 does not include movable doors, flaps, or othercomponents to selectively open and close the inlet and outlet 708, 709,the UAV may include sealing members that seal the inlet and outlet 708,709 closed while the battery 700 is in the UAV. FIG. 7B shows thebattery 700 positioned in a UAV. The UAV may include a battery supportmember 718, which may define a portion of a battery cavity or chamber ofthe UAV. The UAV may also include cover members 716, which may engagethe battery 700 to cover and/or block the inlet and outlet 708, 709. Insome cases, the cover members 716 include compliant seals such as anelastomer, foam, o-ring, or other component that forms an intimate sealagainst the battery 700 to prevent and/or limit air, moisture, liquids,or other fluids and/or contaminants from entering the battery 700. Inother cases, the cover members 716 may lack compliant seals, and maysimply occlude, cover, or otherwise block the inlet and outlet 708, 709.

FIG. 8A illustrates a partial cross-sectional view of another examplebattery 800, which may be an embodiment of the battery 110 (FIG. 1 )and/or the battery 500 (FIG. 5A), with the battery 800 positioned over athermal management apparatus 810. The battery 800 includes a pluralityof battery cells 804, and defines an air duct 802 in thermalcommunication with the cells 804. The air duct 802 may define or be incommunication with an inlet 805 and an outlet 807 (FIG. 8B). The battery800 may include doors 806, 808 that cover the inlet and outlet 805, 807,and are openable to allow air to flow into the battery through the airduct 802. The doors 806, 808 may be mechanically biased in a closedposition, as shown in FIG. 8A. For example, the doors 806, 808 may bebiased closed with springs, elastomers, living hinges, or any othersuitable mechanism and/or material.

The doors 806, 808 may be mechanically opened when the battery 800 isengaged with another component such as a thermal management apparatus810 (which may be an embodiment of the rack charger 220). For example,as shown in FIG. 8A, a thermal management apparatus 810 may include dooractuating members 812 that engage the doors 806, 808 and move them froma closed position to an open position when the battery 800 is placed onand/or engaged with the thermal management apparatus 810. Once placed onthe thermal management apparatus, the doors 806, 808 are opened so thatair can pass through the supply duct 814, through the air duct 802 ofthe battery, and out the exhaust duct 816. FIG. 8B shows the battery 800engaged with the thermal management apparatus 810 such that the dooractuating members 812 have engaged the doors 806, 808 and forced theminto an open configuration such that a stream of air 818 may passthrough the air duct 802 and thermally condition the cells 804.

FIG. 8C shows the battery 800 installed in a UAV or other suitablevehicle. As noted above, the doors 806, 808 may be biased in a closedposition such that when the battery 800 is installed in a UAV or othervehicle, the doors 806, 808 are closed without requiring any dedicatedcomponents or systems in the UAV. In other cases, the doors 806, 808 maybe forced into a closed position by door closure features or mechanismsof the UAV, where the door closure features or mechanisms are configuredto force the doors closed when the battery is coupled to the unmannedaerial vehicle (either via direct engagement with the doors or via alinkage or other mechanism). In some cases, the doors 806, 808 areforced into an open or partially open position by the UAV, for example,to allow air to pass through the air duct 802 during flight operations.

While FIGS. 8A-8C illustrate simple door actuating members 812 thatdirectly force the doors 806, 808 open, other types of mechanisms mayalso be used. For example, the battery 800 may include linkages, cams,gears, or other mechanisms that are operative to open and/or close thedoors 806, 808 when the battery 800 is installed in or otherwise usedwith various different components. For example, the battery 800 mayinclude actuation tabs or levers with which a thermal managementapparatus (e.g., the rack charger 220) may engage to open and/or closethe doors 806, 808. Accordingly, the doors 806, 808 may be opened and/orclosed without direct contact between the doors and the thermalmanagement apparatus. In cases where a UAV or other vehicle selectivelyopens and/or closes the doors during a mission, the vehicle may use thesame actuation tabs or levers to control the position of the doors.

In some cases, thermal conditioning of a battery may be performed duringflight. In some cases, the battery and/or the UAV may include heatingand/or components (e.g., Peltier devices, heating coils, heatexchangers, etc.) that can be controlled by the UAV and/or the batteryto change, modify, maintain, or otherwise control the temperature of thebattery.

In some cases, the battery and UAV may leverage the air duct in abattery to facilitate thermal management of the battery while in flight.FIG. 9 illustrates an example UAV 900 (which may be an embodiment of theUAV 100, FIG. 1 ) with a battery 902 attached. The battery 902 may be anembodiment of any of the batteries described herein. The UAV 900 mayinclude an air intake 904 (and optionally an exhaust) that is configuredto direct air from outside the UAV into the battery 902 to heat and/orcool the battery 902 during flight. In particular, some of the airflowing along the fuselage of the UAV 900 during flight may be forcedinto or otherwise captured by the intake 904 and directed into, over, oralong the battery 902, or otherwise used to thermally condition thebattery 902.

In some cases, the UAV 900 includes sensors to determine the airtemperature of the outside air during flight and to determine thetemperature of the battery during flight. The UAV 900 may also beconfigured to determine whether the outside air can and should be usedto heat and/or cool the battery 902 during flight. In some cases, theUAV 900 monitors the temperature of the battery 902 during flight todetermine if thermal conditioning of the battery is warranted. Thermalconditioning may be warranted if the battery temperature has reached orapproaches a threshold temperature. In some cases, the UAV 900 mayattempt to maintain the battery 902 at a desired target temperature(e.g., 25° C., or any other suitable temperature). If the battery 902 isabove that temperature and if the air temperature outside the UAV iscapable of cooling the battery, the UAV 900 may use air flow from theintake 904 to cool the battery 902. If the air temperature is notcapable of cooling the battery (e.g., because the air is too hot), theUAV 900 may determine not to use air flow from the intake 904, as doingso would be counterproductive. In such cases, the UAV 900 may take noaction or may use other techniques to cool the battery 902. A similartechnique may be used to determine whether to heat the battery (e.g., ifthe battery 902 is below the target temperature and the air temperatureis above the target temperature, the UAV 900 may use air from the intake904 to heat the battery 902).

The ability of the UAV 900 to actively thermally condition the battery902 using external air flow may be accounted for in the batterypreconditioning techniques described herein. For example, when thetarget initial temperature for a battery is determined, thedetermination may account for the predicted ambient air temperatureduring the flight, along with the ability of the UAV to use that air tocool or heat the battery. Thus, for example, if the flight path includesa segment requiring high battery output (and thus a temperature spikefor the battery), a low target initial temperature may be selected sothat the temperature spike does not exceed a threshold value. If thatsegment occurs where the air temperature is predicted to be cold, and ifthe UAV can harness that cold air to actively cool the battery, theinitial-temperature selection algorithm may account for the predictedambient temperature (and the UAV's effectiveness in using that air forcooling) and determine a higher target initial temperature. That is,because the UAV would be able to cool the battery during that segment,the battery need not be cooled as much as it might otherwise. Thisexample further illustrates how using actual forecasted or predicted airtemperatures at different locations along a flight path may be used tomake highly tailored and customized determinations of target initialbattery temperatures for individual missions.

FIG. 10A is a partial cross-sectional view of the UAV 900 and thebattery 902, viewed along line B-B in FIG. 9 . The battery 902 ispositioned on an interior portion of the fuselage of the UAV 900, suchas in a battery cavity. The UAV 900 includes a supply duct 1010 (whichmay be in fluid communication with the intake 904) and an exhaust duct1012 (which may be in fluid communication with an exhaust or fluidoutlet that vents to the ambient environment of the UAV 900). Thebattery 902 may be an embodiment of the battery 800, and in particularmay include doors 1006, 1008 that are similar in structure and/orfunction to the doors 806, 808 in FIGS. 8A-8C. In particular, the doors1006, 1008 may be biased in a closed position by a spring or othersuitable biasing member.

The UAV 900 may also include door actuators 1014, 1016 that areconfigured to selectively open and/or close the doors 1006, 1008. Thedoor actuators 1014, 1016 may be any suitable actuators or othercomponents that can apply a force to the doors 1006, 1008 or to anothercomponent of the battery 902 to cause the doors to selectively openand/or close. In some cases, the door actuators 1014, 1016 are orinclude solenoids, pneumatic actuators, linear motors, rotary motors,lead screws, servos, magnets, electromagnets, or the like.

The door actuators 1014, 1016 may be controlled by the UAV 900 tofacilitate thermal conditioning of the battery 902 during flight. Forexample, when the UAV 900 determines that a condition for thermalconditioning of the battery is satisfied (e.g., when the battery shouldbe cooled and the external air is suitable for cooling), the UAV 900 maycause the door actuators 1014, 1016 to open the doors 1006, 1008, asshown in FIG. 10B, thereby allowing a stream of air 1018 to be directedfrom the supply duct 1010, through the air duct of the battery 902, andout the exhaust duct 1012. When thermal conditioning is not requiredand/or not possible due to the target battery temperature and/or theambient air temperature, the door actuators 1014, 1016 may be operativeto close the doors 1006, 1008, as shown in FIG. 10A.

The air that is directed through the battery 902 may be directed intothe supply duct 1010 from the air intake 904 (FIG. 9 ), and may beexhausted from the UAV 900 at any suitable location. In some cases, theintake 904 and any exhaust port or vent may be positioned at anysuitable location on the UAV 900 and may have any suitable shape, size,and/or configuration. For example, the intake 904 and any exhaust portsor vents may be configured so as to reduce or limit negative aerodynamicimpact on the UAV 900. Also, the UAV 900 may include intake and/orexhaust vent doors, flaps, or other components or systems that can beused to selectively open and/or close the air intake and/or exhaustports or vents. For example, the UAV 900 may include a retractableintake scoop (or other selectively openable and closeable component)that can be selectively closed when thermal conditioning operations arenot active in order to reduce aerodynamic drag, and selectively openedwhen thermal conditioning operations are active. Similarly, the UAV 900may include a retractable (or otherwise selectively openable andclosable) exhaust port or vent that can be opened when thermalconditioning operations are active and closed when they are inactive.

In the examples of FIGS. 5-10B, air is shown as flowing in one directionthrough a battery. However, air may be flowed through the battery in theopposite direction, and/or may be flowed through the battery inalternating directions. Alternating the direction of air flow may helpimprove thermal conditioning efficiency and/or speed. Further,alternating the direction of air flow may help maintain a more constanttemperature throughout the battery (e.g., reducing temperature gradientsin the battery along the direction of the air flow).

Further, while these examples thermally condition the battery by flowingair through a duct in the battery, other types of thermal conditioningmay also be used, such as liquid heating/cooling, cooling and/or heatingplates in contact with a heat-transfer surface of the battery, ovens,electric blankets, external convection (e.g., blowing hot and/or coldair over an exterior heat-transfer surface), and the like. In the caseof liquid heating and/or cooling, the battery may include a liquidconduit that carries liquid through the battery to thermally conditionthe cells. A liquid heating and/or cooling system may be an open system,where liquid is introduced into an inlet and ejected via an outlet, or aclosed system where the liquid is sealed within the battery and isheated and/or cooled via heat exchangers, radiators, or the like.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not targeted to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings. Also, when used herein to referto positions of components, the terms above and below, or theirsynonyms, do not necessarily refer to an absolute position relative toan external reference, but instead refer to the relative position ofcomponents with reference to the figures.

What is claimed is:
 1. A method of preconditioning a battery for use inan unmanned aerial vehicle unmanned aerial vehicle, comprising: fluidlycoupling a fluid channel of a thermal management apparatus to an openingin fluid communication with the battery; determining a predictedtemperature change of the battery as a result of the unmanned aerialvehicle traversing a predetermined flight path; determining a targetinitial temperature for the battery, wherein the target initialtemperature is based at least in part on the predicted temperaturechange and configured to operate the battery within a preferredtemperature range during traversal of the predetermined flight path;selectively actuating a covering of the opening to allow air from thefluid channel of the thermal management apparatus to the battery; and atleast one of heating or cooling the battery to the target initialtemperature by directing air to the battery.
 2. The method of claim 1,wherein the opening is defined in part by an air duct extending from thebattery to an external surface of the unmanned aerial vehicle, the airduct defined in part by a feature of a fuselage of the unmanned aerialvehicle.
 3. The method of claim 2, wherein the air duct allows the airto pass over a plurality of cells of the battery.
 4. The method of claim2, further comprising: launching the unmanned aerial vehicle after thebattery is heated or cooled to the target initial temperature; andactuating the covering to direct air to the battery to selectively heator cool the battery during traversal of the predetermined flight path.5. The method of claim 1, wherein: the battery comprises: an enclosurehousing a plurality of cells of the battery, and an air duct defined inpart by the enclosure and extending from the opening to the plurality ofcells; and the operation of thermally conditioning the battery comprisespassing a stream of conditioned air through the air duct.
 6. The methodof claim 1, wherein the covering is one or more doors.
 7. The method ofclaim 1, wherein the predicted temperature change is at least partiallybased on one or more of a weather condition of at least a portion of thepredetermined flight path, a thermal condition of at least a portion ofthe predetermined flight path, a distance of the predetermined flightpath, a condition of the battery, an energy requirement to traverse thepredetermined flight path, or a power requirement to traverse a portionof the predetermined flight path.
 8. The method of claim 1, furthercomprising: prior to heating or cooling the battery to the determinedtarget initial temperature: charging the battery; and while charging thebattery, performing at least one of heating or cooling the battery tothe target initial temperature.
 9. The method of claim 1, furthercomprising: launching the unmanned aerial vehicle when the batteryreaches the target initial temperature.
 10. A method of conditioning abattery for use in an unmanned aerial vehicle unmanned aerial vehicle,comprising: determining a target battery temperature for the battery ofthe unmanned aerial vehicle based on flight conditions for a plannedflight path of the unmanned aerial vehicle, wherein the target batterytemperature is configured to limit a duration that the battery operatesabove or below a threshold temperature during traversal of the plannedflight path; fluidly coupling a channel of the thermal managementapparatus to an opening in fluid communication with one or more cells ofthe battery to perform at least one of heating or cooling the battery tothe target charging temperature; at least one of heating or cooling thebattery to the target battery temperature, wherein: the heating orcooling is based on a predicted temperature change of the battery as aresult of the unmanned aerial vehicle traversing the planned flightpath, and wherein the operation of at least one of heating or coolingthe battery comprises passing a stream of air from the channel to thebattery; and clearing the unmanned aerial vehicle for launch when thebattery is at the target battery temperature.
 11. The method of claim10, further comprising: determining a target charge specification forthe battery, the target charge specification including an energy orpower requirement to traverse the predetermined flight path; chargingthe battery, wherein the thermal management apparatus is operativelyassociated with a battery charging system; and wherein the targetbattery temperature is based in part on the target charge specificationor a temperature change of the battery due to charging.
 12. The methodof claim 10, wherein the target battery temperature is based in part ona current temperature of the battery.
 13. The method of claim 12,wherein: the opening is defined by a portion of an external surface ofthe unmanned aerial vehicle; a cover selectively provides access to theopening; and the cover is in fluid communication with the air duct ofthe thermal management apparatus during the heating or cooling of thebattery.
 14. The method of claim 12, wherein the stream of air passesdirectly over the one or more cells of the battery.
 15. An unmannedaerial vehicle battery conditioning system comprising: the unmannedaerial vehicle comprising: a fuselage; and a battery removably coupledto the fuselage, the battery comprising: a plurality of cells, and anenclosure housing the plurality of cells; an inlet and an outlet on anexternal surface of the unmanned aerial vehicle, the inlet and theoutlet selectively covered by one or more doors; and an air ductextending from the inlet and outlet to the plurality of cells; and athermal management apparatus comprising: a thermal analysis systemconfigured to determine a target temperature for the battery, whereinthe target temperature is based at least in part a predicted temperaturechange of the battery as a result of the unmanned aerial vehicletraversing a predetermined flight path, and a thermal management systemfluidly coupled to the inlet and the outlet to provide treated airconfigured to at least one of heat or cool the battery to the targettemperature.
 16. The unmanned aerial vehicle battery conditioning systemof claim 15, wherein the battery is positioned under an external surfaceof the unmanned aerial vehicle.
 17. The unmanned aerial vehicle batteryconditioning system of claim 15, wherein the battery is oriented at anangle relative to the external surface.
 18. The unmanned aerial vehiclebattery conditioning system of claim 15, the battery further comprising:a matrix material coupled to the plurality of cells to hold the cells inan orientation within the enclosure; and wherein the matrix materialtransfers or absorbs heat from the plurality of cells.
 19. The unmannedaerial vehicle battery conditioning system of claim 15, wherein thethermal management apparatus further comprises: a channel in fluidcommunication with the air duct to provide the treated air to at leastone of heat or cool the battery; and one or more heat exchanging systemsoperatively coupled to the channel.
 20. The unmanned aerial vehiclebattery conditioning system of claim 15, further comprising: a batterycharging system configured to provide electrical energy to the battery.